JPH07300587A - Spacer for liquid crystal - Google Patents

Abstract

PURPOSE:To obtain a spacer having a non-releasable adherent layer and used for a liquid crystal by forming the adherent layer from graft chains starting from the vinyl groups introduced into the surface of a specified particle, composed of a polymerizable vinyl monomer and being adherent to the orientation substrate. CONSTITUTION:This spacer is formed by introducing polymerizable vinyl groups into the surface of a particle having active hydrogen atoms by reaction with an isocyanate compound having a polymerizable vinyl group and forming an adherent layer composed of graft polymer chains starting from the polymerizable vinyl groups, composed of at least one polymerizable vinyl monomer and being adherent to the orientation substrate. Desirably, this graft chain has a primary side chain adherent to the orientation substrate. More desirably, the primary side chain has a secondary side chain starting from the introduced polymerizable vinyl group, composed of at least one polymerizable vinyl monomer and being adherent to the orientation substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal spacer interposed between a pair of alignment substrates filled with liquid crystal.

[0002]

2. Description of the Related Art As a spacer for liquid crystal of this type, silica particles or metal oxide particles whose surfaces are coated with an adherent such as a low melting point synthetic resin or wax having adhesiveness to an alignment substrate are provided. (JP-A-63-94224)
issue). When the above-mentioned liquid crystal spacer is used, the spacer is fixed to the surface of the alignment substrate via the adhesive layer, and the spacer does not move during cutting, liquid crystal injection, or vibration.

[0003]

However, in the above-mentioned conventional spacers for liquid crystal, the adhesive layer is easily peeled off from the particle surface, and the peeled adhesive layer mixes into the liquid crystal side and interferes with the performance of the liquid crystal. was there.

[0004]

As a means for solving the above conventional problems, the present invention introduces a polymerizable compound introduced by reactively adding an isocyanate compound having a polymerizable vinyl group to particles having active hydrogen on the surface. Provided is a spacer for a liquid crystal in which an adhesive layer composed of a graft polymer chain having adhesiveness to an alignment substrate, which is composed of one or more polymerizable vinyl monomers starting from a vinyl group, is formed. .

As the spacer for liquid crystal of the present invention, a primary side chain is further formed on the graft polymerized chain, a secondary side chain is further formed on the primary side chain, and a secondary side chain is formed on the secondary side chain. Further, those in which a tertiary side chain of polyalkylene glycol is formed are included.

[Oriented Substrate] As the oriented substrate, a glass plate, a plastic plate, a plastic film, a polyimide-coated glass plate, a plastic plate, or a plastic film is usually used. The polyimide coating is performed by coating a polyimide, or by coating a polyimide precursor and imidizing it by heating.

[Particles] In the present invention, a polymerizable vinyl group is introduced by reactively adding an isocyanate compound having a polymerizable vinyl group to particles having active hydrogen on the surface,
Graft polymerization of one or more polymerizable vinyl monomers starting from the polymerizable vinyl group forms a graft polymer chain having adhesiveness to the alignment substrate. Particles having an active hydrogen on the surface silanol groups (Si-OH) on the surface for example, alcoholic OH group, a carboxyl group (-COOH), a amino group (-NH _2),
Acid amido (-CONH _2), an imino group (-NH), a particle having a functional group having active hydrogen, such as a mercapto group (-SH), such particles having a functional group having the active hydrogen Polymerizable vinyl monomer, a polymerizable vinyl monomer having a functional group that becomes the above-mentioned functional group having active hydrogen by a reaction such as hydrolysis or addition, condensation, ring opening, or a functional group having active hydrogen or A monomer mixture containing a polymerizable vinyl monomer having a functional group capable of reacting with a compound having a functional group which becomes the functional group having active hydrogen by a reaction such as hydrolysis or addition, condensation, ring opening, etc. , The monomer mixture is dissolved, and the polymer based on the monomer mixture is not dissolved.A precipitation polymerization method in which the monomer mixture is polymerized in a solvent to precipitate polymer particles, and obtained by the above precipitation polymerization method. From And the polymer particles brought swollen by said monomer mixture, seed polymerization method or the like to obtain a secondary polymer by polymerizing the said monomeric mixture by radicals incorporated in the polymer particles are applied.

In the above precipitation polymerization and seed polymerization, crosslinked polymer particles using a polyvalent vinyl compound such as divinylbenzene, diallyl phthalate and tetraallyloxyethane as a part of the monomer are desirable. The crosslinked polymer particles have good solvent resistance and heat resistance.

In the above precipitation polymerization and seed polymerization, particles having a true spherical shape and having a uniform particle size distribution suitable as a spacer for liquid crystals can be obtained, and particularly in the case of seed polymerization, large spherical particles can be obtained. To be

After the polymer particles have been produced in this manner, or, if necessary, by a reaction such as hydrolysis or addition, condensation, ring opening, or a functional group having active hydrogen or hydrolysis or addition, condensation, By reacting a compound having a functional group that becomes a functional group having active hydrogen by a reaction such as ring opening, if necessary, further hydrolysis or addition, condensation, ring opening, etc. are carried out, and active hydrogen is added to the surface of the present invention. To produce particles having.

[Introduction of Vinyl Group] In the present invention, a polymerizable vinyl group is introduced by reactively adding an isocyanate compound having a polymerizable vinyl group to the particles having active hydrogen on the surface. Examples of the isocyanate compound having a polymerizable vinyl group include acryloyl isocyanate, methacryloyl isocyanate, allyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate and the like.

[Formation of Graft Polymerization Chain] The particles are prepared by graft-polymerizing one or more polymerizable vinyl monomers from the vinyl group introduced on the surface of the particles as a starting point using a polymerization initiator. A graft polymer chain having adhesiveness to the alignment substrate is formed on the surface.

Examples of the polymerizable vinyl monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, Cyclohexyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, isoamyl acrylate, octyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate,
Benzyl acrylate, nonylphenoxyethyl acrylate, β- (perfluorooctyl) ethyl acrylate, methyl methacrylate, ethyl methacrylate, n-
Propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, isobornyl methacrylate, octyl methacrylate, isooctyl methacrylate, cetyl methacrylate, behenyl Methacrylate, isodecyl methacrylate, tridecyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, glycidyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,
3-tetrafluoropropyl methacrylate, 2,2,3,4,4,4-
Hexafluorobutyl methacrylate, β- (perfluorooctyl) ethyl methacrylate, methoxy polyethylene glycol monomethacrylate, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, iso-butyl vinyl ether, allyl glycidyl ether, styrene, α- Methylstyrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl fluoride,
Vinylidene fluoride, ethylene, propylene, isoprene,
Monomers such as chloroprene and butadiene are used.
Examples of the polymerization initiator include benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, t-butyl peroxide, t-butylperoxybenzoate, t-butylperoxy. -2-
Ethyl hexanate, t-butyl peroxypavarate,
Peroxide polymerization initiators such as t-butyl peroxy neodecanoate, 3,5,5-trimethylhexanoyl peroxide, diisopropylbenzene hydroperoxide, lauroyl peroxide and dicumyl peroxide, 2,2 ' -Azobisisobutyronitrile, 2,2'-azobismethylbutyronitronitrile, 2,2'-azobis-2,4-
Dimethylvaleronitrile, 2,2'-azobis-2-cyclopropylpropionitrile, 2,2'-azobis-4-methoxy
-2,4-Dimethylvaleronitrile, 1,1'-azobiscyclohexane-1-carbonitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis-N,
An oil-soluble polymerization initiator such as an azo-based polymerization initiator such as N'-dimethyleneisobutyramidine is mainly used.

The above-mentioned graft polymerization is usually carried out by alcoholic solvents such as methanol, ethanol, iso-propanol, n-butanol, iso-butanol, t-butanol, cyclohexanol, etc., ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone. Solvent, ester solvent such as ethyl acetate, n-butyl acetate, amyl acetate, aromatic solvent such as benzene, toluene, xylene, organic solvent such as cellosolve solvent such as cellosolve acetate, methyl cellosolve, ethyl cellosolve, n-butyl cellosolve In the presence of.

[Formation of Primary Side Chain] Particles having a graft-polymerized chain on the surface thereof, which has adhesiveness to the above-mentioned oriented substrate, can be used as a spacer for a liquid crystal as such. A primary side chain having adhesiveness to may be formed. In this case, the graft polymer chain need not necessarily have adhesiveness to the alignment substrate.

In order to form the above-mentioned primary side chain, a polymerizable vinyl group is introduced into the side chain of the above graft polymerized chain, and one or more polymerizable vinyl monomers are introduced from the polymerizable vinyl group as a starting point. Graft-polymerize. In order to introduce a polymerizable vinyl group into the side chain of the above graft polymerized chain, a silanol group (Si-OH) or Si-H is introduced into the graft polymerized chain as in the case of introducing a polymerizable vinyl group into the particle surface. a group, alcoholic OH group, a carboxyl group (-COOH), a amino (-NH _2), acid amido (-CONH _2), an imino group (-NH), an active hydrogen such as a mercapto group (-SH) A method in which a functional group or a functional group that becomes the above-mentioned functional group having active hydrogen by a reaction such as hydrolysis or addition, condensation, ring opening, etc. is introduced, and an isocyanate compound having a similar polymerizable vinyl group is reactively added. Alternatively, a Si-H group is introduced by reacting silazane to the functional group of the graft-polymerized chain into which the functional group having active hydrogen is introduced, and further a glycidyl group (epoxy group) is added to the Si-H group. The olefin compound having a by reacting added to form a polymerizable graft chain containing a low polymerizable olefin, the Si
A method of reacting an alkyl acrylate or methacrylate having a polymerizable unsaturated bond of acrylate or methacrylate with a —H group, a method of reacting a polymerizable vinyl monomer having a hydrolyzable silyl group with the above Si—OH group, the above Si A method of reacting an epoxy compound having a hydrolyzable silyl group with an -OH group to introduce an epoxy group, and reacting a polymerizable vinyl monomer having an amino group with the epoxy group, wherein the Si-OH group is hydrolyzed. Of reacting an amine compound having a polymerizable silyl group to introduce an amino group, and reacting the polymerizable vinyl monomer having an epoxy group with the amino group, a halogen is obtained by reacting the above Si-H group with a halogenated olefin. And reacting with a polymerizable vinyl monomer having a carboxyl group, the above Si-OH
A method of reacting divinylsilazane with the group or the like is applied.

To introduce the above-mentioned functional group having active hydrogen into the graft-polymerized chain, for example, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl. Methacrylate,
Polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, allyl alcohol, acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate, acrylamide, A polymerizable vinyl monomer having a functional group having active hydrogen such as methacrylamide is used. Further, in order to introduce a Si-OH group into the graft polymer chain, for example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyl. Diethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxypropylbis (trimethoxy) methylsilane, 11-methacryloxyundecamethylenetrimethoxysilane, vinyltriethoxysilane, 4-vinyltetramethylenetrimethoxysilane, 8 -Vinyl octamethylene trimethoxysilane, 3-trimethoxysilylpropyl vinyl ether, vinyltriacetoxysilane, p-trimethoxysilylstyrene, p-triethoxysilylstyrene, p-trimethoxysilyl-α-me Cylstyrene, p-triethoxysilyl-α-methylstyrene, γ-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, N-β (N-vinylbenzylaminoethyl-γ-aminopropyl) trimethoxysilane ・
A polymerizable vinyl monomer having a hydrolyzable silyl group such as hydrochloride is used.

By graft-polymerizing one or more polymerizable vinyl monomers using a polymerization initiator with the vinyl group introduced into the side chain of the graft-polymerized chain as a starting point, the graft-polymerized chain is formed. Form primary side chains that are adhesive to the alignment substrate. As the polymerizable vinyl monomer, the same type as the polymerizable vinyl monomer used when forming the graft polymer chain is used, and a polymerization initiator is also used when forming the graft polymer chain. The same kind as that used is used. Then, the graft polymerization is usually carried out in the presence of an organic solvent as in the case of forming the graft polymerization chain.

[Formation of Secondary Side Chain] Particles having a graft polymer chain having a primary side chain having adhesiveness to the above-mentioned oriented substrate formed on the surface thereof can be used as a spacer for liquid crystal as such. A secondary side chain having adhesiveness to the alignment substrate may be formed on the side chain. In this case, the graft polymerized chain and the primary side chain do not necessarily have adhesiveness to the alignment substrate.

In order to form the secondary side chain, a polymerizable vinyl group is introduced into the side chain of the primary side chain, and one or more polymerizable vinyl monomers are originated from the polymerizable vinyl group. Is graft-polymerized. The method of introducing a polymerizable vinyl group into the side chain and the method of graft-polymerizing one or more polymerizable vinyl monomers starting from the polymerizable vinyl group are the case of forming a primary side chain in the graft-polymerized chain. It is the same.

[Formation of Tertiary Side Chain] Particles having a graft polymer chain having a primary side chain and a secondary side chain having adhesiveness to the above-mentioned alignment substrate on the surface are used as a spacer for a liquid crystal. However, a polyalkylene glycol tertiary side chain having adhesiveness to the alignment substrate may be further formed on the secondary side chain. In this case, the graft polymerized chain, the primary side chain and the secondary side chain do not necessarily have to have adhesiveness to the alignment substrate.

To form the tertiary side chain, a functional group capable of reacting with a hydroxyl group or a carboxyl group is introduced into the secondary side chain, and polyalkylene glycol or a mono- or dicarboxylic acid of polyalkylene glycol is introduced into the functional group. React. Examples of the functional group capable of reacting with the hydroxyl group include a carboxyl group, an isocyanate group, and a glycidyl group (epoxy group). Examples of the functional group capable of reacting with the carboxyl group include a hydroxyl group, an isocyanate group, and a glycidyl group. (Epoxy group) and the like. Then, in order to introduce the functional group into the secondary side chain, a polymerizable vinyl monomer having the functional group is polymerized into the secondary side chain or mixed with another polymerizable vinyl monomer and copolymerized. . Examples of such a polymerizable vinyl monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid (above carboxyl group-containing polymerizable vinyl monomer, 2-hydroxyethyl methacrylate, 2-hydroxy). Ethyl acrylate, 2-
Hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, allyl alcohol, hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate (above hydroxyl group-containing polymerizable vinyl monomer), to introduce a polymerizable vinyl group on the particle surface Isocyanate group-containing polymerizable vinyl monomers similar to those used, glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether, acrylates or methacrylates containing alicyclic epoxy groups (above glycidyl group-containing polymerizable vinyl monomers ) Etc.

[0023]

In the present invention, one or more polymerizable vinyl monomers are polymerized from the vinyl group introduced on the surface of the particle as an origin, and the adhesion is formed by the graft polymerization side chain having adhesiveness to the alignment substrate. Since the layer is formed, the adhesion layer is covalently bonded to the particle surface and does not separate from the particle surface. Further, if a primary side chain, a secondary side chain, or a tertiary side chain having adhesiveness to the oriented substrate is formed on the graft polymerized chain, the thickness of the adhesive layer is gradually increased and the adhesiveness is improved.

[0024]

【Example】

[Example 1] (Introduction of SiOH) 30 g of hydroxypropyl cellulose having a molecular weight of 1.0 x 10 ⁵ , 8 g of styrene monomer, 4 g of γ-methacryloxypropyltrimethoxysilane, 250 of ethyl alcohol.
0.1 g of 2,2'-azobisisobutyronitrile was charged in a reactor, and dispersion polymerization was carried out at 65 ° C. for 10 hours under a nitrogen stream to obtain an average particle diameter of 5.8 μm and a standard deviation of 1.
5% uniform particles were obtained. After washing the above particles, the particles are treated with an acid or an alkali so that Si--O
Cross-linking of -Si siloxane bond, cross-linked particles A having silanol groups (Si-OH) on the particle surface were synthesized.

Example 2 (Introduction of --OH) 2 g of n-butyl peroxide was mixed with sodium lauryl sulfate (0.2 g).
The emulsion was finely dispersed in 20 g of water in which 15 g was dissolved so that the oil droplet diameter was 0.5 μm or less. The above initiator dispersion was added to 40 g of an aqueous dispersion of 5 wt% polystyrene particles (particle diameter 1.2 μm) and slowly stirred at 30 ° C. for 12 hours to absorb the oil droplets of the initiator into the polystyrene particles. To obtain a seed particle dispersion. Then 45 g of styrene, 15 of 2-hydroxypropyl methacrylate
g, and a monomer mixture of 10 g of divinylbenzene are finely dispersed in 350 g of water in which 2.85 g of sodium lauryl sulfate is dissolved, and the seed particle dispersion liquid is added and mixed to the dispersion liquid, and the seed particles are mixed with The body mixture was absorbed. Thereafter, 100 g of a 10 wt% aqueous solution of polyvinyl alcohol was added to the above dispersion liquid, and the temperature was raised to 80 ° C. to polymerize the monomer mixture absorbed by the seed particles. Six hours after the temperature was raised, the above monomer disappeared, and uniform spherical particles having an average particle size of 7 μm and a standard deviation of 4.5% were obtained. By treating the particles with an acid or an alkali, crosslinked particles B having alcoholic OH groups on the surface were synthesized.

Example 3 (Introduction of —COOH) Hydroxypropyl cellulose having a molecular weight of 4 × 10 ⁵ 50
g, 10 g of styrene, 5 g of divinylbenzene, 2 g of methacrylic acid, 300 g of methyl alcohol, 0.2 g of 2,2'-azobisisobutyronitrile were charged in a reactor, and 60
By carrying out dispersion polymerization under nitrogen stream for 8 hours at 6.degree. C., the average particle size having -COOH groups is 6.25 .mu.
m, standard deviation 3%, crosslinked particles C were synthesized.

[Example 4] (Introduction of SiH group) The silanol group (-
SiOH), or 10 g of each of particles A to C having active hydrogen such as an alcoholic OH group and a carboxyl group (—COOH), 30 g of toluene and 30 g of tetramethyldisilazane are charged all at once, and the mixture is heated at 80 to 90 ° C. for 3 ~
Crosslinked particles D having Si-H groups on the surface after reacting for 5 hours
Got

Example 5 (Introduction of SH Group) To 10 g of particles A having SiOH groups on the surface, 20 g of toluene, and a monomer having simultaneously a hydrolyzable silyl group and a mercapto group (for example, mercaptopropyltrimethoxysilane). ) 30g in a batch, 80-90 ℃
At room temperature for 5 to 7 hours to obtain crosslinked particles E having a mercapto group on the surface.

Example 6 (amino group (or imino group)
Preparation of Introduced Particles) A monomer (for example, 4-aminobutyltriethoxysilane) 3 having an amino group or an imino group simultaneously with a hydrolyzable silyl group per 10 g of particles A having a SiOH group on the surface 3
0 g and 20 g of toluene were charged all at once and reacted under reflux of toluene for 5 to 7 hours to obtain particles F having an amino group or an imino group on the surface.

[Example 7] (Production of amide group-introduced particles) On the surface prepared in Example 3, a carboxyl group (-COO
To 10 g of the particles C having H), 20 g of toluene and 30 g of diamines (for example, 2,4-diaminotoluene) are charged all at once, and the reaction is carried out for 1 to 2 hours while removing water produced under reflux of toluene. Particles G having an amide group were obtained.

[Example 8] (Production of vinyl group-introduced particles) To 10 g of the crosslinked particles B having alcoholic OH groups on the surface prepared in Example 2, 3 g of a 30% toluene solution of methacryloyl isocyanate and 20 g of methyl ethyl ketone were used.
g was charged all at once and reacted at 20 to 25 ° C. for 30 to 60 minutes to introduce a vinyl group on the particle surface.

[Example 9] (Production of vinyl group-introduced particles) Crosslinked particles D to F1 having SiH groups, mercapto groups and amino (or imino) groups on the surfaces prepared in Examples 4 to 6
20 g of methyl ethyl ketone and 3 g of a 30% solution of methacryloyl ethyl isocyanate in 3 g of 0 g were charged all at once and reacted at 20 to 25 ° C. for 30 to 60 minutes to introduce a vinyl group on the particle surface.

Example 10 (Production of Vinyl Group-Introduced Particles) Particle G10 having an amide group on the surface prepared in Example 7
20 g of methyl ethyl ketone and 3 g of a 30% solution of methacryloyl isocyanate in 3 g were collectively charged and reacted at 100 to 150 ° C. for 1 to 2 hours to introduce a vinyl group on the particle surface.

Example 11 (Production of Grafted Primary Side Chain Formed Particles Using Polymerizable Vinyl Monomer) For 10 g of particles having vinyl groups introduced on the surface prepared in Examples 8 to 10, Polymerization initiator (for example, 2,2′-azobisisobutyronitrile) 1 g, methyl cellosolve 10
Charge 0 g to raise the temperature to the initiator cleavage temperature, and under a nitrogen stream 2
The reaction is carried out for a time to generate radicals in the vinyl group on the particle surface. After 2 hours, 50 g of a polymerized vinyl monomer (for example, 2-hydroxypropylmethacrylate etc.) that has an OH group and a homopolymer can be dissolved in methyl cellosolve is added dropwise, and after reacting for 1 hour, an adhesion layer composed of graft polymer chains is formed on the surface. Particles are produced. The particles are washed with methyl cellosolve and then dried. Again to 10 g of the particles, methacryloyl isocyanate 30% toluene solution 3
g, 20 g of methyl ethyl ketone are charged at once
By reacting at 25 ° C. for 30 to 60 minutes, particles H having a vinyl group introduced into the side chain of the graft polymerized chain are produced. The particles are washed with methyl ethyl ketone and then dried.
To 1 g of the particles, 0.1 g of a polymerization initiator (for example, 2,2′-azobisisobutyronitrile) and 10 g of toluene were charged, the temperature was raised to the cleavage temperature of the initiator, and the mixture was reacted for 2 hours under a nitrogen stream to give a particle surface. Radicals are generated in the vinyl group of the graft polymer chain. After 2 hours, 5 g of a polymerizable vinyl monomer (for example, styrene, methyl methacrylate, vinyl acetate, etc.) in which the homopolymer can be dissolved in toluene was added dropwise, and when the reaction was carried out for 1 hour, the graft polymer chain started from the vinyl group. A primary side chain composed of a polymer chain of the polymerizable vinyl monomer is formed. The particles having the graft-polymerized chain having the primary side chain thus produced as an attachment layer are washed with toluene and then dried. As a result of SEM (scanning electron microscope) measurement of the particles, the increase in particle size was Δd = 0.3 μm.

Example 12 (Production of Grafted Secondary Side Chain-Formed Particles Using Polymerizable Vinyl Monomer) A vinyl group was introduced into the side chain of the graft-polymerized chain obtained in Example 11. To 10 g of the particles H, 100 g of methyl ethyl ketone, 30 g of methyl methacrylate, 20 g of 2-hydroxypropyl methacrylate and 1 g of a polymerization initiator (for example, benzoyl peroxide) were charged all at once, and the reaction was carried out at 80 ° C. for 2 hours under a nitrogen stream to give the graft-polymerized chain. Starting from the vinyl group, a primary side chain composed of a polymer chain of the polymerizable vinyl monomer containing an OH group is formed. The particles are washed with methyl ethyl ketone and then dried. To 10 g of the particles, again, 3 g of a 30% solution of methacryloyl isocyanate in toluene and 20 g of methyl ethyl ketone were charged all at once, at 30 to 60 at 20 to 25 ° C.
Particle reaction is carried out to produce particles I having a vinyl group introduced into the primary side chain of the graft polymerized chain. The particles are washed with methyl ethyl ketone and then dried. A polymerization initiator (for example, benzoyl peroxide) is added to 1 g of the particles.
When 0.1 g, 10 g of methyl ethyl ketone and 5 g of a polymerizable vinyl monomer (for example, glycidyl methacrylate) were charged all at once and reacted at 70 to 80 ° C. for 2 to 3 hours under a nitrogen stream, the vinyl group was formed on the primary side chain of the graft polymerization. A secondary side chain composed of a glycidyl methacrylate monomer polymer chain is formed starting from the group. The particles having the secondary side chain as an attachment layer thus produced are washed with methyl ethyl ketone and then dried. As a result of SEM (scanning electron microscope) measurement of the particles, the increase in particle size was Δd = 0.6 μm.

[Example 13] (Production of particles having a grafted secondary side chain using a polymerizable vinyl monomer and a macromonomer) A vinyl group was introduced into the side chain of the polymer chain prepared in Example 11. 20 g of methyl cellosolve per 1 g of the grafted particles H
g, thermoplastic macromonomer having one or more polymerizable vinyl groups in the molecule (eg, methoxypolyethylene glycol monomethacrylate) 10 g, polymerization initiator (eg, peroxide initiator such as benzoyl peroxide, 2,2 ′) -
Azo initiators such as azobisisobutyronitrile) 0.1
Grafts are charged all at once, the temperature is raised to 60 to 80 ° C. under a nitrogen stream, the reaction is carried out for 1 hour, and then the excess polymer is removed, whereby graft particles having a thermoplastic polymer layer on the surface are produced. The graft particles are washed with methyl cellosolve and then dried. As a result of SEM measurement of the particles, the increase in particle size was Δd = 0.25 μm.

Example 14 (Production of Grafted Tertiary Side Chain-Formed Particles Using Polyalkylene Glycol) For 10 g of particles I having a vinyl group introduced into the primary side chain of the graft-polymerized chain prepared in Example 12 , 1 g of a polymerization initiator (for example, 2,2′-azobisisobutyronitrile), 100 g of methyl cellosolve, and 50 g of a polymerizable vinyl monomer (for example, glycidyl methacrylate) having a functional group capable of reacting with a hydroxyl group or a carboxyl group at once Charge to
When reacted at 70 to 80 ° C. for 2 to 3 hours under a nitrogen stream, a graft secondary side chain having a functional group capable of reacting with a hydroxyl group or a carboxyl group from the vinyl group as a starting point is formed on the graft polymerization primary side chain. It To 1 g of the particles, 30 g of methyl cellosolve and 10 g of polyethylene glycol dicarboxylic acid (average molecular weight of 200 or more) were charged all at once.
Reaction is carried out under reflux of methyl cellosolve for 2 to 6 hours to remove excess polyethylene glycol dicarboxylic acid, and drying is performed. The particles thus produced having the tertiary side chain as an attachment layer are easily dispersed in water, melt at low temperature, and exhibit adhesion to the alignment film. As a result of measurement of the graft particles by SEM (scanning electron microscope), increase in particle size Δd =
It was 1.2 μm.

[Example 15] (Production of Grafted Tertiary Side Chain-Formed Particles Using Polymerizable Vinyl Monomer and Macromonomer) A vinyl group was introduced into the side chain of the polymer chain prepared in Example 11. 20 g of methyl ethyl ketone for 1 g of graft particles H
g, macromonomer 10 g having one or more polymerizable vinyl groups in the molecule and one or more epoxy groups, polymerization initiator (for example, peroxide initiator such as benzoperoxide, 2,2'-azo 0.1 g of azo initiator such as bisisobutyronitrile) is charged at once, and the temperature is 60 to 80 ° C. under a nitrogen stream.
After the reaction is carried out for 1 hour, the excess polymer is removed, and thus graft particles having a polymer layer containing an epoxy group on the surface are produced. The graft particles are washed with methyl ethyl ketone and then dried. To 1 g of the graft particles, 10 g of dimethylformamide, 3 g of a macromonomer having one or more carboxyl groups in the molecule (eg stearic acid, polyethylene glycol dicarboxylic acid, etc.)
Were charged all at once, and the mixture was refluxed for 2-6 under dimethylformamide reflux.
The reaction is carried out for a time to produce graft particles having a thermoplastic polymer layer on the surface. The graft particles are washed with dimethylformamide and then dried. SEM of the particles
As a result of the measurement according to, the increase in particle size was Δd = 0.5 μm.

The following tests were conducted on the graft particles obtained in Examples 11 to 15. [Test 1] (Impurity elution test for liquid crystal) 0.1 g of each graft particle was replaced with 1 g of liquid crystal (Merck: ZLI
−1565) and allowed to stand at 150 ° C. for 24 hours, after which the liquid crystal was extracted and subjected to differential scanning calorimetry (DS
The liquid crystal resistance was examined by C) and gas chromatography (GC). In addition, 0.5 g of each graft particle
After being immersed in iso-propanol and left at room temperature for 10 days, the amount of impurities was measured using a spectrophotometer (UV). The results are shown in Table 1.

[0040]

[Table 1] * Comparative example: 5.3 μm synthesized by sol-gel method
The silica particles having a particle size and 5 g of methyl methacrylate resin particles having a particle size of 0.25 μm were mixed to adsorb the resin.
The silica particles having adsorbed resin were coated by heat treatment to prepare silica particles having an organic adhesive layer having a thickness of 0.1 μm, and the particles were used as a comparative example. According to Table 1, it was found that impurities were not mixed into the liquid crystal from the graft particles of the present invention at all, whereas the particles of Comparative Example had a lowered liquid crystal purity. From this, it was confirmed that the graft-fixed particles of the present invention did not impair the orientation of the liquid crystal.

[Test 2] (Fixing Performance to Substrate with Polyimide Alignment Film) 0.1 g of each of the particles prepared in Examples 11 to 15 and the particles of Comparative Example and silica particles was added to iso-propanol 5
g, and ultrasonic dispersion was performed for 10 minutes, and then 1.
It was sprayed onto an imide substrate (a polyimide was used by firing San-Ever SE-150 manufactured by Nissan Kagaku Co., Ltd. under the standard firing conditions of the catalog) at an air pressure of 0, 2.0 Kg / cm ² . The substrate was fired for 10 minutes under the temperature conditions of 100 ° C., 120 ° C., 150 ° C. and 180 ° C., and the adherence of the particles of the present invention was evaluated by the bead residual rate by the air blow method. The results are shown in Table 2.

[0042]

[Table 2] From Table 2, it can be seen that the particles of the present invention are considerably superior in stickiness to the comparative particles.

[0043]

Therefore, according to the present invention, it is possible to obtain a liquid crystal spacer which has good adhesion to the alignment substrate and does not peel off the adhesion layer.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Hironori Hata 8-3 Ninomachi, Mizuho-ku, Nagoya, Aichi Natco Paint Co., Ltd.

Claims (4)

[Claims] 1. From one or more polymerizable vinyl monomers starting from a polymerizable vinyl group introduced by reactively adding an isocyanate compound having a polymerizable vinyl group to particles having active hydrogen on the surface. A spacer for liquid crystal, characterized in that an adhesive layer composed of a graft polymer chain having adhesiveness to an oriented substrate is formed. 2. The spacer for liquid crystal according to claim 1, wherein the graft polymerized chain is further formed with a primary side chain having adhesiveness to the alignment substrate. 3. A polymerizable vinyl group is introduced into the primary side chain, which is composed of one or more polymerizable vinyl monomers starting from the polymerizable vinyl group and attached to an alignment substrate. The spacer for liquid crystal according to claim 2, wherein a secondary side chain having properties is formed. 4. A functional group capable of reacting with a hydroxyl group or a carboxyl group is introduced into the secondary side chain, and orientation is performed by reacting the functional group with a polyalkylene glycol or a mono- or dicarboxylic acid of polyalkylene glycol. The spacer for liquid crystal according to claim 3, wherein a polyalkylene glycol tertiary side chain having adhesiveness to the substrate is formed.